It was the moral appeal that Dr. King used to help broaden the struggle to end institutional discrimination in the South. Dr. King understood that the battle between his forces and those in the position of power in the South could not be fought on the traditional battlefield. Rather, Dr. King had to take a page out of Gandhi's playbook and Thoreau's thinking and make a political and social struggle a moral one. In arguing that segregation is not merely illegal, but morally unacceptable, Dr. King was able to broaden the struggle and the fight to include Northerners and individuals who were White. In embracing this moral stature, the non- violent and civil disobedient stand taken helped to enhance King's moral stature, making his battle more acceptable and more universal. This created such a moral chasm between he and those who practiced segregation that the weight of the outside world ended up playing a vital role in stopping Southern institutional segregation.

Clearly, the civil rights movement won their battle to end segregation. However, I would not say that the movement really undermined the culture of Jim Crow.

Instead, I would say that the movement got enough support outside the South to push through laws that ended segregation even though the South still wanted it.

There were lots of outside elements that contributed. The two main ones I would mention are

Movement of blacks to the North in WWII. There, they could vote and they became an important voting bloc in some parts of the North.

Cold War -- made the US want to look good in the eyes of the world and that meant that high government officials thought it was in our best interests to end segregation so that black and brown people around the world would like us.